In recent years, there is proposed a light-emitting element package having a light emitting diode (hereinafter, referred to as a “LED”) as a light-emitting element installed on the light-emitting element package. For example, the proposed light-emitting element package or the like is formed by plural groups of LEDs, each of which is made of three LEDs that are mounted on a wiring pattern on an upper surface of a flexible substrate, and plural radiator plates are provided by a bond so as to cover a portion corresponding to a mounting position of the plural groups of LEDs, as disclosed in Japanese Laid-open Patent Publication No. 2003-92011.
However, the above light-emitting element package is to radiate heat emitted by the groups of LEDs by providing the radiator plate at a portion corresponding to the position of mounting the groups of LEDs. Because a heat radiation route from the groups of LEDs to the radiation plate is insufficient, heat emitted by the groups of LEDs cannot be efficiently transferred to the radiator plate.